选择了哪个JRadioButton

Question

我在一个ButtonGroup中有几个JRadioButtons。

   private ButtonGroup radioGroup= new ButtonGroup();
   private JRadioButton radio1= new JRadioButton("Red");
   private JRadioButton radio2= new JRadioButton("Green");
   private JRadioButton radio3= new JRadioButton("Blue");

   radioGroup.add(radio1);
   radioGroup.add(radio2);
   radioGroup.add(radio3);

如何确认选择了哪一个？

对于System.out.println(radioGroup.getSelection())，我只能得到像javax.swing.JToggleButton$ToggleButtonModel@32b3714这样的东西。

Answer 1

从选定的ButtonModel中，您可以获得actionCommand字符串(如果您记得设置它！)。

// code not compiled, run, nor tested in any way
ButtonModel model = radioGroup.getSelection();
String actionCommand = (model == null) ? "" : model.getActionCommand():
System.out.println(actionCommand);

但这只有在您首先设置actionCommand的情况下才能起作用。例如：

// code not compiled, run, nor tested in any way
String[] colors = {"Red", "Green", "Blue"};
JRadioButton[] radioBtns = new JRadioButton[colors.length];
for (int i = 0; i < radioBtns.length; i++) {
   radioBtns[i] = new JRadioButton(colors[i]);
   radioBtns[i].setActionCommand(colors[i]);
   radioGroup.add(radioBtns[i]);
   somePanel.add(radioBtns[i]);
}

Answer 2

您看到的是toString方法的默认实现。ButtonGroup#getSelection将返回所选JRadioButton的ButtonModel。

另请参见How do I get which JRadioButton is selected from a ButtonGroup。

Answer 3

如果附加了侦听器，则确定来源的一种简单方法是调用ActionEvent.getSource()。